The invention relates to an apparatus for selective catalytic oxidation of carbon monoxide in a hydrogen-rich mixed gas flow.
An apparatus of this generic type and having a plate-type construction, which is intended to reduce the proportion of carbon monoxide in the gas produced by a water-vapour reformer, is disclosed in DE 195 44 895 C1. In this arrangement, plates with reaction chambers and heat-exchanger chambers are stacked on one another alternately. Each plate has four through-openings in each case for the mixed gas flow or heat carrier medium inlet and outlet. In order to allow air to be supplied with a different volume flow in each stage, holes can also be provided on the end faces of the plates having the reaction chambers, through each of which holes air can be metered into the reaction chambers. However, additional components need to be provided in order to distribute the air.
Furthermore, DE 87 09 386 U1 discloses an apparatus for using a probe, arranged in the flow direction of the first gas, in order to apply a second gas to a reaction chamber through which gas flows.
WO-A-97 25752 describes a multistage apparatus for selective catalytic oxidation of carbon monoxide, which comprises a plurality of plates, stacked on behind the other.
EP-A-0 776 861, which forms the prior art, discloses a method and apparatus for selective catalytic oxidation of carbon monoxide. In the disclosed apparatus, plates having reaction chambers and heat-exchanger chambers are alternately stacked one on top of the other. Air is supplied at the end faces of the reaction chambers.
The object of the invention is to provide an apparatus for selective catalytic oxidation of carbon monoxide in a hydrogen-rich mixed gas flow, with simplified supply and mixing for the oxidizing gas.
This object is achieved by the apparatus according to the invention.
Integration of the supply for the oxidizing gas into the inlet channel for the mixed gas flow represents a solution that is simple and cost-effective for production. In a first advantageous configuration, the supply ends in the manifold channel, where there is no catalyst material. There is thus no need for any additional mixing path or distributor structures. Furthermore, the ratio of the reaction and cooling chambers to one another can be varied as required, in terms of volume and/or the number of plates.
A plurality of stages can be integrated in one physical unit, without any problems. In this case, high flexibility is nevertheless maintained by the variable inlet position for supplying the oxidizing gas. Overall, the apparatus according to the invention has improved characteristics in terms of volume requirement, weight and costs.
Advantageous configurations of the apparatus for supplying the oxidizing gas results in reliable homogenization of the gas mixture between each individual stage.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.